Thermostat



Dec. 29 1925 F. W. ROBERTSHAW TiERMosTAT Filed July 24, 1925 uw mw ww NV,

l INV'NTOR fnl/wf /w Patented Dec. 29,' 1925.

'UNITED STATES PATENT OFFICE.

FREDERICK W. ROBERTSHAW, F PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 BOB- EBTSHAW THERMOSTAT COMPANY, 0F YOUNGWOOD, PENNSYLVANIA7 A CDR- POBATION F PENNSYLVANIA.

THERMOSTAT.

Application fuea'ruly 24, i923. serial no. esa-ieri To all wlwm t may concern:

Be it known that I, FREDERICK W. ROBERT- sHAw, a citizen of the United States, residing at Pittsburgh, county of Allegheny, and

f State of Pennsylvania, have invented a new and useful Improvement in Thermostats, of which the following is a full, clear, and exact description.

The present invention relates broadly to thermostats, and more particularly to thermostats of the character adapted to be used in connection with valves, such as gas valves, to provide combinations suitable for use with ovens, although it will be apparent that its use in this respect is not limited. v

The construction herein illustrated may be of the general character shown in Patent No. 1,455,663 of May 15, 1923, issued jointly to George A. Robertshaw and myself, but is adapted to provide improved means for preventing any leakage between the valve chamber and the body of the thermostat, and also to assist in maintaining the parts in y the desired adjusted position.

-It will be understood that the embodiment of the invention shown in the accompanyin drawings is for purposes of illustration on y, as changes may obviously be made in the constructlon and o eratlon disclosed without departing from t e spirit of my invention or scope of my broader claims.

In the drawin s: t

Figure 1 is a ongitudinal sectional view through the valve and its o rating thermostat, certain of the parts bemg broken away and certain of the parts being shown in elevation; and

Figure 2 is a view similar to Figure 1, but on an enlar ed scale, illustrating in detailA certain of tIi In the form of invention illustrated, there is provided a supportin body 2 which may be in the form of a valve casing having a suitable inlet connection 3 and an outlet connection 4, these parts constituting a portion of one form of controlling device. Intermediate the portsof these connections the casing may be provided witha seat 5 adapted to cooperate with a valve 6, for cutting oli communication between the orts. The

valve is normally urged in the irection of the seat'byfsuitable means such as a spring 7 For accurately-guiding the valve during :its opening and closing movements, it may Aby the provision of I'an improved e features of construction..

be formed with a stem 8 extending into a boss 9 projecting inwardly :from the casing. Access to the casing for inspection or renewal of parts is permitted by removing a closure 10 it being apparent that the closure is removable at will without disturbing. the Setting of any other parts of the combination. The .usual bypass, as customary in lthe art, and as clearly shown in the patent referred to, may be utilized.

Extending rearwardly from the supporting body or valve casing is a projection 11 havin a threaded outer surface. This threa which may be either single or double, is preferably of comparatively steep pitch. Cooperatively threaded thereon is a revolving couple or adapter l2 having one end provided with an internal thread corresponding to the threads on the projection 11, and hav'- ing its o posite end internally threaded with a threa of different pitch, for example a standard thread, adapted to receive the threaded end 13 of an expanding element 14.

Within the expansible member is a nonexpansible member 15 of suitable material abutting against a packing pin 16 separate from, and in alinement with, the valve stem 8. Heretofore considerable difficulty has been encountered in attempting to 'provide a gas tight joint between t e interior of the valve casing and the interior of the member 14. If the in 16 has been made with a tight enough t to prevent gas leakage, the eicient operation of the valve, particularly under the action of the spring 7, has been impaired. In accordance with the present invention, this objection is obviated acking which may comprise a body of suitab e pack- ,ing 17 adapted to be compressed by a packing gland 18. Thepacking gland 1n turn is urged longitudinally ofthe packing pin to compress the packing by means of a sprlng 19. At its opposite endthis spring may abut; against the shoulder 20 or the end of the member 14. It will be .apparent that this construction maintains a tight seal around the packing pin-to prevent any leakage, and that by using a spring of proper scale any binding is prevented.

On the exterior of the casing 2, so asto be visible to a user throughout itsl entlre length, is a plate 21 having suitable graduations thereon' v'indicating different degrees of;-

i temperature at which it may be desired -and thermostat, an

maintain the oven or other means being controlled. Clamped about the revolving couple 12 is an arm 22 provided with an oper ating handle 23 and cooperating with the graduations of the late 21. By moving .the handle 23 it will apparent that the revolving couple will be rotated, thereby moving the same toward or away from the suport or casing 2, by means of the thread projection il. s movement is amplified byI reason of the high pitch ont the threads so as to' move the mem-r ber 14 as may be desired for the required operation of the valve 6.

.lt has been found that the spring 19 also serves an important function in connection with the couple 12, and the adjustment of the parts.- 'lhis is true for the reason that the spring maintains a tension on the c0- operating threads, thereby maintaining the handle 23 in the osition to which it is moved. This is highly desirable, articularly when used with ovens and the ioike, as the closing and opening of the oven door does not change the setting. Y

Certain advantages of the present invention arise from the provision of a revolving couple between a supporting body carrying the member to be actuated and the thermostat, together with means for maintaining the revolving couple-in adjusted position.

Still other advantages of the invention arise from the provision of improved packing means preventing the leakage of any gas from the chamber of the valve being actuated into the interior of the thermostat and thencg to the oven or the like.

1. The combination with a thermostat and a valve forl actuation said controlling means for preventing leaka pointer 24, the latter thereby, of separate l threaded contmllin means between the valve means-cooperating *withI age from the valve into the thermostat and for maintaining a load on said threads, substantially as described.

2. rlhe combination with a thermostat Aand a valve tor actuation thereby, of operating means Ibetween the valve and thermostat, comprising a threaded couple and a pin, and a spring-pressed packing cooperating with both of said means to prevent leakage around the pin and past the threads of such couple, substantially as described.

3. A thermostat, comprising a supporting body, a member movably mounted thereon a heat responsive device for actuating said member, necting said member and device, and means for maintaining said couple in adjusted position, substantially as described.

4l. ln a thermostat, a valve, a thermostatic element, an operating pin between said valve and element and separate therefrom, 'and means for packing said pin, said means also tending to maintain the thermostat in adjusted position, substantially as described.

5. ln a thermostat a valve, a thermostatic element, an adjustable revolving couple connecting said valve and element for adjusting the thermostat, and means within said couple tor preventing leakage between said valve and thermostat and tending to maintain the thermostat in adjusted position, substantially as described.

6. In a thermostata valve, a thermostatic element, a revolving couple connecting said valve and element and movable for adjusting the thermostat, and spring pressed packing within said couple for preventing leakage between said valve and thermostat and maintaining a load on said couple, substantially as described.

an adjustable revolving couple'conf lin testimony whereof l have hereunto set my hand.

FREDERICK W. nonnn'rs 

